Modern patient care in a hospital or other health care facility requires the preparation and intravenous or intramuscular administration of very large numbers of parenteral solutions to patients. Such solutions include those for both nutritional purposes, as well as drug-containing therapeutic solutions.
In view of the very large numbers of such solutions which must be handled on a daily basis in a health care facility, efficient and accurate preparation and administration of such solutions is highly desirable. To this end, one very significant advancement in recent years has been the development of positive displacement fluid infusion pumping devices for intravenous or intramuscular administration of solutions to patients. Such systems have, in large measure, replaced the previously employed gravity flow control systems, primarily due to their much greater accuracy in delivery rates and dosages, and their relative sophistication in permitting flexible and controlled feed from multiple liquid sources. In particular, such infusion pumping devices permit precise control of drug administration to a patient over a given period of time.
U.S. Pat. No. 4,639,245, to Pastrone et al., U.S. Pat. No. 4,818,186, to Pastrone et al., and U.S. Pat. No. 4,842,584, to Pastrone, all of which are hereby incorporated by reference, disclose a positive displacement fluid infusion pumping device and components thereof which has met with widespread acceptance by the patient care field. This pumping system includes the combination of a pump driver and an associated removable and disposable pump cassette. The pump cassette includes a self-contained positive displacement pump device, which is operated in the desired manner by a reciprocable pump plunger of the associated pump driver. The pump driver further includes selectively operable valve actuators, which actuators cooperate with a plurality of valve mechanisms provided in the pump cassette, with the system thus providing accurate and highly automated administration and infusion of parenteral solution.
The present invention is directed to a solution pumping system including a disposable pump cassette which will permit the same highly-desirable efficiency, accuracy, and automation in the compounding and preparation of such parenteral solutions. While the present system is particularly suited for preparation of so-called small volume parenteral solutions, typically including drugs or other therapeutic agents for administration to patients, the principles disclosed herein are equally suitable for a system for preparation of large volume parenterals, typically comprising nutritional solutions for patients, as well as for use with other applications requiring compounding of multiple reagents or therapeutic agents.
At present, the pharmacies at hospitals and other health care facilities typically admix small volume parenteral solutions manually The pharmacist selects an intravenous solution container, typically a bag, that is either partially empty, or that contains the appropriate base nutritional solutions or diluents. The pharmacist or assisting personnel then calculates the amounts of the various liquid components that need to be added to the solution container in accordance with the physician's order. These components are then measured by drawing them into syringes of the appropriate sizes. The contents of the syringes are then injected into the final solution container.
As will be appreciated, accurate preparation of parenteral solutions in this manner is time consuming, typically taking on the order of 20-30 minutes per physician order, assuming about 10 minutes of preparation time per bag when making three bags with six solution additions per bag. While appropriate protocols are established and followed for accuracy and consistency, the manual nature of the procedure does not preclude the possibility of errors in the preparation of the resultant admixtures. Additionally, the repeated needle-puncturing and additions of solutions to the admixture container increase the risk of contamination.
The present solution pumping system, including a disposable pump cassette, is particularly configured to facilitate accurate and efficient compounding of parenteral admixture solutions with minimal labor and a risk of contamination, particularly those of a relatively small volume containing drugs and like therapeutic agents, by eliminating manual addition of different source solutions, with the system lending itself for use with automated and programmable controls for further enhancing accuracy and efficiency.